Device for removing slag from heating surfaces of waterwall tubes in the boiler



3,411,419 S QF Dec. 24, 1968 z. ZIEBINSKI DEVICE FOR REMOVING SLAG FROM HEATING SURFACE WATERWALL TUBES IN THE BOILER Filed Oct. 3. 1966 2 Sheets-Sheet 1 INVENTOR.

Z YGMUN T Z/EBl/VSK/ Z. ZlEBlNSKl Dec. 24, 1968 DEVICE FOR REMOVING SLAG FROM HEATING SURFACES 0F WATERWALL TUBES IN THE BOILER 2 Sheets-Sheet. 2

Filed Oct. 3, 1966 nited States ABSTRACT OF THE DISCLOSURE Apparatus for cleaning the heating surfaces of radiant tubes in boilers, including a rotatable drum rotatably mounted on a vehicle frame and carrying a plurality of articulated hammers. Means are provided to guide the vehicle frame along the tubes along with means to vary the speed of the vehicle.

Disclosure The present invention relates to a device designed for removing slag from the heating surfaces of waterwall tubes in boilers.

According to known methods, slag is removed from boiler tubes by knocking off the slag by means of a hammer, by scraping it off by means of a scraper, and by grinding. Also, in situations where the slag crust is not very hard, it has been suggested to remove it by a water jet under pressure, or pneumatically by shot blasting.

The disadvantage of the last-mentioned method is that the heat insulation is wasted when cleaning. Also, all these methods require the expenditure of much labor and they may be applied only when scaffolding is used, which is very difficult to manipulate.

The purpose of the present invention is to eliminate these disadvantages by utilizing a mechanical device traveling along the waterwall tubes of the boiler without using scaffoldings, without requiring hard manual work, and to reduce the time of the operation.

An example of the device according to the present invention is shown in the drawings, in which:

FIG. 1 is a top plan view of the traveling device;

FIG. 2 is a cross-sectional view taken along line A-A of FIG. 3;

FIG. 3 is a side elevational view of the traveling device; and

FIG. 4 is a diagrammatic view of the traveling device in a boiler along with its auxiliary equipment.

The main components of the mechanical traveling device of the present invention include a rotary drum 1 with articulated hammers 13 driven from an electric motor 6 through a gearbox 15, a drive shaft 25, and a linked chain 14 extending around toothed wheels on shafts 1 and 25 to operatively connect the latter. The rotating drum rests upon two brackets 4, one of which is completely shown in FIG. 1. The gearbox 15 has an additional shaft 2 for driving a rope-sheave 3 moving the device up and down along the guide wire ropes and 7, which are wrapped around the rope-sheave 3 in opposite directions. The ropesheave 3 consists of two identical cones, each receiving a wire rope 5 or 7 so that when the sheave is rotated in one direction, one rope is Wound on, and the other un- 3,4374% Patented Dec. 24, 1968 ice wound from, the sheave. The purpose of the conical surfaces is to prevent overlapping of the winding coil by the unwinding one when the ropes are loaded by weights 19, as the rope being wound on the sheave 3 would otherwise press the unwinding rope down on the cone.

As shown in FIG. 3, two wheel sets are provided on the traveling device, each wheel set comprising an electrolmagnet shaft 11, an electromagnetic coil 10, and two running wheels 12 through which the magnetic flux flows to hold down the traveling device on the waterwall 9 with a certain electromagnetic force, it being understood that the force may be regulated in any known manner.

Additionally, the jenny is guided upon the tubes to be cleaned by the guide roll 8, which may be mounted between two sets of wheels 12 in any known manner, such as shown by the dash lines in FIG. 2, for example. All

these components are mounted on a mounting plate 16,

as shown.

For driving the traveling device up and down the tube walls with a controlled speed, the rope sheave 3, guide wire ropes 5 and 7, control rods 17 and 18, and the weights 19 are utilized in a manner described in detail later, which speed may be controlled according to the various thickness of slag crust on the walls.

As shown in FIG. 4, a swinging beam 20 is utilized for establishing the initial position of the traveling device on the boiler tubes. The vertical position of beam 20 is controlled with a wire rope 21 fixed to beam 20, and a wire rope 22 controls the relative angular position of the beam.

The operation of the device is as follows. The traveling device of FIGS. 1-3 is shown by the reference numeral 30 in FIG. 4, and is hung from one end of beam 20 by means of the guide ropes 5 and 7 which are coiled around their respective conical surfaces of sheave 3 in opposite directions, as described above. Weights 19 and control rods 17 and 18 are fixed to the respective free ends of guide ropes 5 and 7. Then the motor 6 and the electromagnet shaft 11 are switched on in any known manner and the device moves in a predetermined direction with the hammers 13, due to their centrifugal force, striking against the slag formed on and between the tubes to remove it. Travel of the device in one direction causes one guide rope 5 or 7 to be unwound from one conical sur face of sheave 3 and the other guide rope to be wound onto the other conical surface of sheave 3. The tension of the latter rope can be regulated by manipulating the control rod 17 and 18 in the directions shown by the arrows in FIG. 4 to regulate the friction drive connection between the rope and sheave 3 to control the speed of the traveling device 30. Of course, when the direction of travel is reversed, the other guide rope 5 or 7 will then be wound on the sheave, and its tension and friction drive connection regulated in a similar manner. Also, the control of the electromagnetic force exerted by shaft 11 may be regulated as desired.

What I claim is:

1. Apparatus for cleaning the heating surfaces of radiant tubes in boilers comprising a vehicle frame, a rotatable drum rotatably mounted on said frame, a plurality of hammers pivotally mounted on said drum, a sheave rotatably mounted on said frame, and a pair of externally supported guide ropes coiled around said sheave in opposite directions, the free ends of said ropes extending freely from said frame, drive means to drive said drum and said sheave, and means to selectively control the tension in each of said ropes to regulate the speed of said vehicle.

2. The apparatus of claim 1, further comprising at least one electromagnetic roller rotatably mounted on said frame and adapted to engage said tubes.

3. The apparatus of claim 1, further comprising a guide roller carried by said frame and adapted to engage a boiler tube.

4. The apparatus of claim 1, further comprising a support member movably mounted in said boiler and adapted to support said guide ropes.

4 References Cited UNITED STATES PATENTS EDWARD L. ROBERTS, Primary Examiner. 

